نتایج جستجو برای: neutron dosemetry

تعداد نتایج: 46142  

Journal: :iranian journal of science and technology (sciences) 2009
m. haji-shafeieha

beryllium chemical combination has a considerable effect on the design and fabrication of the241am9be neutron source. in this investigation the beryllium combinations were studied as a generator ofneutrons with various mass percentage, and the neutron yields were also calculated using the results of thealice and srim codes calculations per unit incident charge. the neutron yields of beryllium ...

G.A. Mercado, H.R. Vega-Carrillo, R. Barquero,

Background: In high-intensity, mixed and pulsed neutron fields the use of spectrometers or area monitors with active detectors is useless in these conditions neutron measuring devices must have a passive detector. Here a passive neutron area monitor with CR39 track detector was designed and the response was calculated. Materials and Methods: The response of a passive neutron area monitor with C...

Journal: :iranian journal of radiation research 0
h. miri-hakimabad radiation detection and measurement laboratory, ferdowsi uinvesity of mashhad, mashhad, iran h. panjeh radiation detection and measurement laboratory, ferdowsi uinvesity of mashhad, mashhad, iran a. vejdani-noghreiyan radiation detection and measurement laboratory, ferdowsi uinvesity of mashhad, mashhad, iran

background: prompt gamma neutron activation analysis (pgnaa) is known as a non-invasive technique capable of measuring elemental concentration in voluminous samples in a short period of time. also it is a valuable diagnostic tool for total body elemental measurements. 252cf and 241am-be sources which are usually used in this method, generate not only neutrons, but also emit high-energy and unwa...

Journal: :journal of biomedical physics and engineering 0
m t bahreyni toossi medical physics department, faculty of medicine, mashhad university of medical sciences, mashhad, iran b khajetash medical physics department, faculty of medicine, mashhad university of medical sciences, mashhad, iran m ghorbani medical physics department, faculty of medicine, mashhad university of medical sciences, mashhad, iran

background: one of the main causes of induction of secondary cancer in radiation therapy is neutron contamination received by patients during treatment. objective: in the present study the impact of wedge and block on neutron contamination production is investigated. the evaluations are conducted for a 15 mv siemens primus linear accelerator.  methods: simulations were performed using mcnpx mon...

ژورنال: سنجش و ایمنی پرتو 2017

In this work, a neutron irradiating system containing six Am/Be neutron sources in a graphite moderator, which produces a relatively high and uniform thermal neutron flux in an irradiating cavity at the center of the system , has been  simulated .The thermal neutron flux in the center of the system has then been calculated and compared with experimental results  measured in a cavity a...

Introduction: Neutron contamination is very harmful for the patients receiving radiation therapy due to the high relative biological effect of neutrons. Medical linear accelerators head are made up of materials with high atomic numbers, and High-energy photons interaction with heavy materials can produce neutron contamination. In this study, neutron equivalent dose, neutron spe...

Introduction: Environmental and occupational human exposure from neutron source can lead to the serious biologic effects. The aim of this study is to evaluate the cancer incidence risk for various human organs at different neutron dose levels due to exposure from an Americium-241/Beryllium (Am-241/Be), a standard neutron source for calibration purposes. Material and Methods: We measured ambient...

A. Ghasemi Janghjoo, A. Mesbahi, E. Mansouri, M. Okutan, R. Malekzadeh,

Neutron sources employed in different applications in both medicine and industry. Due to the harmful effects of neutron particles on living organisms, radiation shields have played a vital role in radiation protection against neutrons. In recent decade, numerous investigations conducted on the design and fabrication of nanocomposites as more efficient shielding materials against fast and therma...

Journal: :iranian journal of radiation research 0
j.g. fantidis department of electrical engineering, technological education institute of eastern macedonia and thrace, saint loucas, kavala, greece a. antoniadis cardiovascular division, brigham and women's hospital, harvard medical school, boston, usa

background: a boron neutron capture therapy (bnct) facility, based on a dt neutron generator, with the final goal to find out a potential, alternative, solution to existing bnct treatment facilities which are based on nuclear reactors is examined. materials and methods: with the aim of the mcnp4b monte carlo code different beam-shaping assembly (bsa) configurations were considered. lead was sel...

Journal: :international journal of nanoscience and nanotechnology 2013
sh. sohrabnezhad* d. rezaei ochbelgh n. morsali golboos

in this research, cobalt and nickel sulfide nanoparticles (nps) were grown on almcm-41 matrix by using ion exchange method. the prepared samples were irradiated by thermalized neutron that emitted from am-be source up to fluencies (7.9+e9n/cm2). after that, x-ray diffraction (xrd), uv-vis spectroscopy, fourier transform infrared (ftir), scanning electron microscopy (sem) and transmission electr...

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